Automatic electrical exchange.



No. 763,412. PATENTED JUNE 28, 1904.

F. A. LUNDQUIST & J. '& C. J. ERICKSON.

AUTOMATIC ELECTRICAL EXCHANGE. APPLICATION rl'nnn DEC. 2. 1898.

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No. 763,412. PATENTBD JUN BZS, 1904. I. A. LUNDQUIST & J. & G. J.ERIGKSON.

AUTOMATIC ELECTRICAL EXCHANGE.

APPLICATION FILED DBO. 2. 1893.

10 sums-sum a.

N0 MODEL.

No. 763,412. 7 PJQUIIEINTED JUNE 28, '1904.

I. A. LUNDQUIST & J. & ,G. L ERIOKSON.

AUTOMATIC ELECTRICAL EXCHANGE.

APPLIQATIDN FILED DEC. 2. 1893.

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No; 763,412. PATENTED JUNE 28, 1904.

F. A. LUNDQUIST '1' & QL 1T. ERICKSON.

AUTOMATIG ELBGTRKGAL EXCHANGE.

APPLIOAJUQE NLRB BBQ. 2. 1893.

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No. 763,412. PATENTED JUNE 28, 1904. F. A. LUNDQUIST & J. & G. J.BRICKSON. AUTOMATIC ELECTRICAL EXCHANGE,

APPLIOATION'TILED DEC. 2. 1893.

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No. 763,412. PATENTED JUNE 28, 1904. P. A. LUNDQUIST & J. & C. J.ERICKSON. AUTOMATIC ELECTRICAL EXCHANGE.

' APPLICATION FILED DBO. z. 1893.

No. 763,412. IPATENTED JUNE 28, 1904.

- F. A. LUNDQUIST & 'J.'& c. J. ERIGKSON.

AUTOMATIC ELECTRICAL EXCHANGE. APPLICATION FILED no. 2. 1893.

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AUTOMATIC ELECTRICAL EXCHANGE.

APPLICATION FILED DBO. 2- 1893 10 SHEETS-SHEET a.

NO MODEL.

No. 763,412. PATENTED JUNE 28, 1904.

F. A. LUNDQUIST & J. & C. LERICKSON.

AUTOMATIC ELECTRICAL EXCHANGE.

APPLICATION FILED DEC. 2. I893- N0 MODEL. 1 0 BHEETS-SHEBT 9.

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No. 763,412. PATENTED JUNE 28, 1904. F. A. LUNDQUIST & J. & G. J.ERIGKSON. AUTOMATIC ELECTRICAL EXCHANGE.

APPLIUATION FILED DBO. 2. 1893.

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UNITED STATES Patented June as, 1904.

PATENT OrFrcE. I

FRANK A. LUNDQUIST, JOHN ERICKSON, AND CHARLES J. ERICKSON, OF CHICAGO,ILLINOIS, ASSIGNORS, BY DIRECT AND MESN E ASSIGNMENTS, TO THEMSELVES,JOHN ANDERSON, OF SALINA, KANSAS, AND GLOBE AUTOMATIC TELEPHONE COMPANY,OF CHICAGO, ILLINOIS, A CORPO- RATION OF ILLINOIS.

AUTOMATIC ELECTRICAL EXCHANGE.

SFEGIFICATION formingpart of Letters Patent No. 763,412, dated June 28,1904.

Application filer. December 2, 1893. Serial No. 492,639. (No m'odeh)cago, in the county of Cook and State of Illinois, have invented certainnew and useful 1m movements in Automatic Electrical Exchanges, of whichthe following 1s a specification, reference being had to theaccompanying TO drawings, in which Figure 1 is a plan view. Fig. 2 is afront elevation. Fig. 3 is a rear elevation. Fig. 4. is a detail, beinga plan view of the circuitclosing arms, showing the way in which theyare mounted and the Wire connections. Fig. 5 is a detail, being apartial vertical section on line 5 5 of Fig. 1. Fig. 6 is a partialsectional view on. line 6 6 of Fig: 2 looking down. Fig. 7 is an endelevation looking to the left in Fig. 2. Fig. 8 is a partial endelevation, being a section on line 8 8 of Fig. 2 looking to the right.Fig. 9 is a diagrammatic view showingthe wire connections of theexchange-switch. Fig. 10 is a diagrammatic vicwshowing the arrangementof the wire connections of the exchange-SWitchboard. Fig. 11 is a planview of the switch-box which is located at substations. Fig.12 is a viewof the under side of the top plate of said box. 3 Fig. 13 is aview ofthe switch-box, the upper plate being removed. Fig. 1A is a side view ofthe switch-box looking to the right in Fig. 11, and Fig. 15 is adiagrammatic view showing the connections between the switch-box and theexchange-switch at the central station which is operated by it. being apartial longitudinal vertical section of the switchboard, showing therelease-magnet and its armature and the connecting parts.

-4 Fig. 17 is a partial vertical cross-section of the switchboard,showing a part of the release-magnet. Fig. 18is avertical cross-sectionof: the substation-switchboard on line 18 18 ofFig. 11. Fig. 19 is avertical cross-section on line 1919 of Fig. 2. Fig. 20 is alongitudinal'vertical section on line 20 20 of Fig.

Fig. 16 is a detail,

19. Fig. 21 is a vertical section on line 21 21 of Figs. 1 and 4; andFig. 22 is a detail, partly in section, showing one of theelectromagnets and its armature.

Our invention relates to automatic electrical exchanges, andparticularly to that class of automatic exchanges which are intended tobe used for making automatic connections in telephone systems betweendifferent subscribers. As is well known, in substantially all of suchautomatic exchange systems each telephone-substation is connected to anexchangeswitch located at a central station, which exchange-switch isadapted to be operated from the substation to connect the subscriber toany other telephone in the system, and our present invention is similarto others in that respect.

One of the objects of our present invention is to improve and simplifythe construction of automatic electrical exchanges not only by improvingthe construction of the exchangeswitch to be used at the central stationand can converse without danger of being broken in upon by others.

We accomplish these objects as hereinafter specified and as illustratedin the drawings.

That which we regard as new will be set forth in the claims.

In describing our invention we will first explain the construction ofthe exchange-switch, which is located at the central station, referringto the accompanying drawings.

The operating parts of the exchange-switch are mounted upon a metallicbase-plate 20, represented in the diagrammatic views by wire 20, whichplate is of suitable shape to carry them and is in turn mounted upon aboard or other suitable support 21, as shown in Fig. 2.

Connections are made between the operators instrument and otherinstruments in the system by connecting the operators exchangeswitchwith the exchange-switches of the different instruments. For instance,if the operator desired to call telephone No. 20 he would connect hisinstrument, through his eX- change-switch, with a wire connected to theexchange-switch of telephone No. 20. It will therefore be understoodthat provision must be made at each exchange-switch for makingconnections with all the other exchangeswitches in the system. To thisend each exchange-switch is provided with a switchboard 22, whichconsists of two non-conducting switchboard-plates 23 24, arranged oneabove the other in a horizontal position and in proximity to each other,as best shown in Fig. 3, each of which plates carries a number ofcontact-points, the contact-points of the two plates 23 24 beingarranged opposite each other on the inner surfaces of said plates. Inorder to provide increased capacity, we provide what may be termed acompound switchboardthat is to say, each switchboard is composed of aplurality of series of contact-points, which in the construction shownare arranged in squares, there being, preferably, one hundredcontact-points in each square. and a separate contact-making device isprovided for each square or series of contact-points on the switchboard.In connection with this apparatus selective switch mechanism is providedby which the circuit may be closed through either of said contact-makingdevices, so that a limited movement only of the different contact-makingdevices is necessary in order to make connection with any contact-pointon the switchboard as a whole.

Our improved construction, broadly considered, by which we provideselective switch mechanism to determine or select which of the differentcontact-making devices is to be used, is one of the important featuresof our present invention, as it makes it practicable to provideexchange-switches suitable for systems employing a much larger number ofinstruments than could otherwise be acc0mmosquare are numbered,beginning at the forward left-hand corner, the first row from front torear being from O to 9, the second row from 1O to 19, &c. The secondhundred contactpointsthat is, those from 100 to 199are contained in thesquare at the rear left-hand corner of the switchboard. The thirdhundred contact-points are in the second square from the forwardleft-hand corner of the switchboard, and so on, the adjacent squaresbeing numbered in alternate hundreds.

In order to provide means whereby any two subscribers who wish to haveprivate communication and wish to avoid being broken in upon by othersmay establish a private connection, each exchange-switch is connected bytwo wires to each of the other exchangeswitches in the system, the twowires from any one exchange-switch being connected to two opposite upperand lower contact-points, and, as will be hereinafter more fullydescribed, means are provided whereby any subscriber can connect hisinstrument at will with either of said two contact-points, and therebycut himself off from outside interruption or not, as he chooses. In thearrangement herein illustrated the squares or contact-points in theforward row of the upper switchboardplate 23 are connected, to what maybe called the general wires that is, the wires which do not affordexclusive connection with other exchange-switcheswhile thecontact-points in the opposite lower row furnish means for securingprivate connection with the same exchange-switches. The contact-pointsat the rear edge of the switchboard are oppositely arranged, the lowerrow of contact point squares being general and the upper private.

The connections through the various contact-points are made by means ofthe following apparatus: 25 indicates a carrier or traveling support inthe form of a rock-shaft which extends longitudinally of the switchboard22 and midway between the two switchboard-plates 23 24:, as best shownin Figs. 2 and 8. The shaft 25 is journaled in bars 26 27, arranged atopposite ends of the switchboard 22, as shown in Fig. 4:, which bars 2627 are supported at their ends by suitable standards 28 29 3O 31 (seeFigs. 7 and 8) and are adapted to move transversely of said switchboard,thereby moving the shaft 25 backward and forward between the twoswitchboardplates. The rock-shaft 25 carries five crossbars 32 33 34 3536, secured midway of their length upon the shaft 25 andadapted to lienormally in a horizontal position between the switchboard-plates 23 24:.The cross-bars above mentioned are further secured in place by means ofa plate 37, which extends lengthwise of the shaft 25, to which it issecured, as shown in Fig. 4. Each of said cross-bars carries at each enda pin 38, which pins are seen red in the respective cross-bars midway oftheir length and perpendicularly to said bars, so that they normally liein a perpendicular position. (See Fig.19.) The pins 38 of each cross-barare spaced a distance apart equal to that which separates anycontact-point in one of the rows of squares from thecorrespondingly-situated contact-point in the other row. By thisarrangement when the shaft is rocked so as to throw the forward ends ofthe bars 36 up the pins 38 at the forward ends of such bars will engagecontact-points in the upper row of squares and the pins at the otherends of said bars will engage correspondingly-situated contact-points inthe lower rear row of squares. The opposite ends of the bars 32 33 34 3536 are insulated from each other, which may be accomplished either bymaking said bars of non-conducting material or by making them ofseparate pieces with some suitable non-conducting material between theadjacent parts.

39 40 41 42 43 indicate bars which are secured upon the rock-shaft 25adjacent to the bars 32 33 34 35 36, respectively, and are electricallyconnected to the rear portions of said bars by connecting-pieces 44, asshown in Fig. 4. The method of connecting the bars 32 33 34 35 36 willbe hereinafter explained.

45 indicates a frame which projects from one end of the switchboard 22and carries a cross-bar 46. The adjacent end of the shaft 25 is providedwith a pin 47, which is adapted to fit into a recess or slot 47 in thebar 46,

as shown in Fig. 21, by which arrangement when the bar 46 is moved inthe frame 45 the shaft 25 will be moved with it. The bar 46 is adaptedto move longitudinally of the exchange-switch, being fitted in slots inthe side pieces 48 49 of the frame 45. By this arrangement the shaft 25is adapted to move longitudinally of the switchboard 22 as well astransversely thereof. The transverse movement of the shaft 25 iseffected by means of a shaft 50, (see Fig. 7,) which is journaled in theframe of the machine and extends longitudinally of the switchboard, asshown in Fig. 2, which shaft is provided at each end with a pinion 51,which pinions are in mesh with racks 52, carried by the bars 26 27, asbest shown in Figs. 5 and 20. The shaft 50 is rotated by means of anelectromagnet 53, marked on Fig. 9 Transverse-movement magnet, arrangedat one side of the exchangeswitch upon the base-plate 20, which magnetis adapted to attract an armature 54, mounted upon a rock-shaft 55,supported by standards 56. The rock-shaft also carries an arm 57, (seeFig. 1,) which projects over a ratchetwheel 58, mounted upon theadjacent end of the shaft 50, as shown inFig. 7. The arm 57 carriesapawl 59, which is adapted to engage the teeth of the ratchet-wheel 58when the magnet 53 is energized. The arrangement is such that when thearmature 54 is attracted by the magnet 53 it will move a sufficientdistance to actuate the arm 57 sufficiently to move the ratchet-wheel 58the space of one tooth.

60 indicates a detent which is pivoted upon the base plate 20 (see Fig.17) and rising therefrom is adapted to engage the teeth of theratchet-wheel 58 to prevent reverse motion thereof. The detent 60 isheld in contact with the ratchet-wheel 58 by a suitable spring. At itslower end the detent 60 is provided with a horizontal arm 61, as bestshown in Fig. 17. By slightly elevating the arm 61, as will behereinafter described, the detent 60 may be thrown out of engagementwith the ratchetwheel 58 to permit the return of the shaft 25 to itsnormal position. In the exchangeswitch herein illustrated theratchet-wheel 58 is arranged to rotate the space of ten teeth, asuitable stop being provided to prevent any further movement of theshaft 25. If desired, however, a greater movement of the shaft could besecured, as would be necessary if the system comprised more than ninehundred and ninety-nine subscribers.

The shaft 25 is returned in part to its normal position (or suchposition that its contactpins 38 he opposite the front rows ofcontactpoints of the two series and at the left-hand ends of such rows)by means of a spring 62,

(see Fig. 1,) one end of which is secured to the standard 30, (see Fig.8,) its opposite end being secured to the rear end of the bar 26, (seeFig. 8,) so that the tension of the spring will 1tend to move the bar 26and shaft 25 forwarc.

The shaft 25 is shifted longitudinally of the switchboard by means of anelectromagnet 63, marked on Fig. 9 Longitudinal-movement magnet, whichis adapted to attract an armature 64, carried by a rocking arm 65,pivoted upon the base-plate 20, as shown in Fig. 3. A suitable springserves to hold the armature 64 normally outof contaetwith the poles ofthe electromagnet 63. The arm 65 carries at its upper end a pawl 66,which is adapted to engage the teeth of a rack 67, which is movablelongitudinally of the exchange-switch. The outer end of the rack 67 isfitted in a suitable bearing in a standard 68, as best shown in Fig. 3,and its inner end is connected to a cross-bar 69, which also moves inthe slots between the side pieces 48 49 of the frame 45, as best shownin Figs. 4 and 7. The bar 69 is connected to the bar 46, as shown inFigs. 1 and 4, so that as the rack 67 moves longitudinally of theexchange-switch the shaft 25 will be moved with it. When the magnet 63is energized, the armature 64 will be attracted and the pawl 66 engagingthe teeth of the rack-bar .67 will move it outward the space of onetooth.

69 (see Fig. 3) indicates a stop which is adapted to engage the end ofthe pawl 66 and prevent it from moving the rack-bar 67 more than onetooth at a time. j

70 (see Fig. 3) indicates a detent which is pivoted upon a rod 71,carried by the frame 45, and extends transversely over the rack-bar 67.(See Fig. 4.) The detent is adapted to engage a second series of teethat the upper side of the rack-bar 67 to prevent the return of saidrack-bar. The detent 70 is moved out of engagement with the rack-bar 67to permit the return of said rack-bar by means of an arm 72,(sec Fig.16,) which rises from the armature 73 of an elcctromagnet 74 (see Figs.1 and 16) and is adapted to engage a depending arm 75, secured to theforward end of the rod 71, as shown in Fig. 16. The magnet 74 is markedReleasemagnet on Fig. 9. The armature 73 is pivoted upon the base-plate20 between suitable blocks 76, so that when the magnet 74 is energizedthe armature 73 will be moved toward it. It is held normally out ofcontact with the poles of the magnet 74 by means of a suitable spring.The arms 72 75 are so arranged that when the armature 73 is attracted byits electromagnet the arm 72 will strike the arm 75 and rock the rod 71sufficiently to move the detent 7 0 out of engagement with the teeth ofthe rack 67. The rack-bar 67 will then be returned to its normalposition by a spring 77, one end of which is connected to an upright 78,connected to the rack-bar 67, (see Figs. 3 and 7,) its other end beingconnected to a suitable stationary support, such as the switchboard 22.(See Fig. 1.) A suit able spring 79 serves to hold the detent 7Onormally in contact with the rack-bar 67, as best shown in Figs. 1 and4. The armature 73 is also provided with an arm 80, which projects underthe arm 61 of the detent 60, as best shown in Figs. 16 and 17, thearrangement being such that when the armature 73 is attracted by theelectromagnet 74 it will raise said arm 61 sufliciently to throw thedetent 60 out of engagement with the teeth of the ratchet-wheel 58,thereby permitting the retation of said ratchet-wheel in a reversedirection.

The normal position of the pins 38 is over the contact-point at theforward left-hand corner of their respective squares. It follows,therefore, from the arrangement of the contact-points which has beenabove described that when the pawl 59 is actuated by the magnet 53 thepins 38 will be moved over the contact-points in each square bearing thenext higher number, and the pins may therefore be moved to the desiredcontact-point by energizing the magnet 53 the proper number of times,provided the desired number is not more than 9? If a higher number isdesired, by energizing the magnet 63 the shaft 25 and the pins 38 willbe moved longitudinally of the switchboard to the right until thedesired row of tens is reached, when the proper number may be secured bymoving the shaft 25 transversely of the switchboard by actuating thepawl 59. For instance, to move the pins 38 into position to make contactwith contact-points connected to telephone No. 35 the magnet 63 would beenergized three times and the magnet 53 five times. By energizing themagnet 74 a single time the shaft 25 and the pins 38 will be returned totheir normal position. ferent magnets above described may be energizedat will from a substation will be hereinafter described.

In order to provide for making connections with instruments numbered inthe hundreds, a non-conducting plate 81 is provided, (see Fig. 1,) whichcarries a series of contactpoints 82, arranged in the arc of a circle,as shown in Figs. 1 and 4. As shown in Fig. 4, the first or left-handcontact-point 82 is connected to the forward end of the arm 32, the pin38 of which arm moves over the square of contact-points located at theforward lefthand corner of the switchboard and numbered from O to 99, asabove set forth. The second contact-point 82 is connected to the bar 39and through it to the rear end of the arm 32, the pin 38 carried bywhich bar moves over the square of contact-points numbered from 100 to199, as above described. The third contact-point is connected to theforward end of the arm 33, the fourth to the rear end of said arm 33,and the remaining contact-points 82 are connected to the remaining arms34 35 36 in the same order. (See Fig. 4.) The wires 91, connecting thecontact-points 82 with the respective arms 32 33 34 35 36 are supportedby a cross-bar 88, which rests upon standards 89 90, rising from thestandards 30 31, as shown in Figs. 2 and 3, which arrangement permitssuch move ment of said wires 91 as is necessary owing to the travel ofthe shaft 25; but this arrangement may be varied.

83 indicates a circuit-closing arm, which is mounted upon a verticalshaft 84, arranged at the front of the exchange-switch and at the centerof the circle of which the contact-points 82 form an are. (See Figs. 1and 6.) The shaft 84 is journaled at its lower end upon the base-plate20 (see Fig. 2) and at its upper end in a cross-bar 85, carried by astandard 86, which rises from the base-plate 20, as best shown in Fig.2. The shaft 84 is adapted to be rotated to move the arm 83 into contactwith the different contact-points 82, thereby closing the circuitbetween them and the base-plate 20. By this construction in order toconnect the base-plate 20 with the square of contact-points numbered inany given hundred by moving the arm 83 into contact with thecorresponding contact-point 82 such connection will be made. The objectof this construction will be more fully set forth hereinafter.

The normal position of the arm 83 is resting upon the left-handcontact-point 82, and

The means whereby the difit is returned to this position by means of aspring 87, carried by the shaft 84. (See Fig. 2.)

The shaft 84 is rotated to move the arm 83 into contact with thedifferent contact-points by means of an eleotromagnet 92, marked on Fig.9 Selective-switch magnet, which is adapted to attract an armature 93.supported by an arm 94, (see Fig. 6,) which is pivoted upon a pivot 95,fixed to the base-plate 20 in such manner that the arm 94 will lie inahorizontal position. At its forward end the arm 94 carries a pawl 96,arranged substantially at right angles therewith. The pawl96 is adaptedto engage the teeth of a segmental ratchet-plate 97, which is securedupon the shaft 84, as best shown in Fig. 6. The arrangement is such thatwhen the magnet 92 is energized the armature 93 will be attracted,moving the arm 94 and causing the pawl 96 to engage the ratchet-plate97, moving it the space of one tooth. The armature 93 is normally heldout of contact with the poles of the magnet 92 by a spring 98, thearrangement of which spring will be hereinafter set forth.

The ratchet-plate 97 is locked against reverse movement by means of a.dog 99, which is adapted to engage the teeth thereof, and is pivotallysupported in a block 100, secured upon the base-plate 20 in a suitableposition. (See Figs. 1 and 2.) The dog 99 is held in engagement with theteeth of the ratchet-plate 97 by a suitable spring 101, as shown in Fig.6. The dog 99 is moved out of engagement with the teeth of theratchet-plate 97 to permit of resetting said plate by means of anelectromagnet 102, (see Fig. 1,) which magnet 102 is adapted to attractan armature 103, which is pivoted in bearings 104 105, mounted upon thebase-plate 20, as best shown in Fig. 1. The magnet 102 is markedReleasemagnet on Fig. 9. The arrangement is such that when therelease-magnet 102 is energized the armature 103 will be attracted, itsupper edge moving toward the poles of said magnet. (See Figs. 1 and 2.)A suitable spring 106 (see Figs. 1 and 2) is provided, which holds thearmature 103 normally out of engagement with the poles of the magnet102. Projecting from the forward end of the armature 103 is a bar 107,which is rigidly connected to said armature, as shown in Fig. 1. Thespring 106 bears against said bar 107. 108 indicates a connecting-rod,one end of which is pivotally connected to the forward end of the bar107, the other end of which is connected to an arm 109, rigidlyconnected to the pawl 99 and projecting therefrom at substantially aright angle. (See Fig. 1.) By this construction when the armature 103 isattracted by the magnet 102 the rod 108 will move in the directionindicated by the arrow in Fig. 1, thereby moving the dog 99 out ofengagement with the teeth of the ratchetplate 97 and permitting the arm83 to return to its normal position under the action of the spring 87.

110 (see Fig. 6) indicates an adjustable stop carried by a post 111,which rises from the plate 20. The stop 110 serves to limit the returnmotion of the ratchet-plate 97, as shown in Fig. 6. From theconstruction just described it will be'seen that the arm 83 may be movedinto contact with any desired contactpoint 82 by energizing the magnet92 a sufiicient number of times and afterward returned to its normalposition by energizing the release-magnet 102 a single time.

We have now described the apparatus used to operate the exchange-switchin such manner as to move the contact-points into position for makingconnections with contactpoints numbered in the units, tens, andhundreds, and it is evident that by operating the different mechanismsin succession the contact-points may be 'moved into position to makeconnection with any desired number from 0 to 999.

Before describing the electrical connections by means of which thedifferent electromagnets are operated from a substation we will describethe apparatus used for tilting the shaft 25 in order to bring thecontact-pins 38 into contact with the different squares on the upper andlower switch-plates.

The end of the shaft 25 opposite to that at which is located the magnet63 is irregular in cross-section, preferably square, as shown in Figs.1, 4, and 8, and is provided with a crosshead 112, as shown in Fig. 8,which crosshead is provided with arms 113 114 at its ends, which projectat right angles thereto, as shown in Fig. 4. The shaft 25 is adapted toslide longitudinally through the cross-head center, as is necessary whensuch shaft is shifted longitudinally of the switchboard, as hereinbeforedescribed. The cross-head 112 is held normally in a horizontal positionby means of springs 115 116, as best shown in Fig. 8.

117 indicates an electromagnet which is arranged in a vertical positionsubstantially opposite the arm 114 of the cross-head 112, as shown inFigs. 1 and 3. The magnet marked 117 is marked General-wire magnet onFig. 9. p i

118 indicates the armature of the magnet 117, which is arranged over thepoles of the magnet 117 and is pivoted to standards 119 120 by means ofarms 121, as best shown in Figs. 1 and 3. A spring 122, mounted upon arod 123, serves to hold the armature 118 normally out of contact withthe poles of the magnet 117 and a short distance above said poles. (SeeFig. 1.)

124 indicates a stop secured to the standard 120 and projecting over theadjacent end of the armature 118, which stop serves to limit the upwardmotion of said armature. (See Fig. 1.)

extends over the arm 114 and is of sufficient length to extend over thepath of the arm 114, i

so that notwithstanding the transverse movement of the shaft 25 andcross-head 112 the arm 114 will at all. times lie under the crossbar126. The arrangement is such that when the magnet 117 is energized andthe armature 118 attracted thereby the cross-bar 126 will be moveddownward into engagement with the arm 114, thereby exerting a downwardjpressure thereupon and causing the shaft 25 to tilt in such manner as tomove the contactpins 38 upon the rear ends of the bars 32 33 34 35 36into engagement with the contactpoints upon the rear edge of the lowerswitchboard-plate 24. At the same time the pins 38 in the forward endsof the bars 32 33 34 1 35 36 will be moved into contact with the con 1tact-points at the forward edge of the upper switchboard-plate 23.

hen the magnet 117 is demagnetized, the spring 122 will lift thearmature 118, thereby j releasing the arm 114 and permitting the springs115 116 to return the cross-head 112 to its horizontal position. 112 istilted in the opposite direct-ion to make connections with the rearupper row of contact-points and the forward lower row of contact-pointsby means of an eleetromagnet 127, marked on Fig. 9 Private-wire magnet,an armature 128, having an arm 129, and a crossbar 130, which is similarto the cross-bar 126 and is arranged over the arm 113. 1.) The magnet127 serves to tilt the arm 125 exactly as described for the magnet 117,and the corresponding parts, except the arm 129 and cross-bar 130, areindicated by the same reference-numerals.

Owing to the hereinbefore-deseribed arrangement of the contact-pointsquares upon the two switchboard-plates, the energizing of the magnet117 operates to make connections over the general wires, whereasenergizing of the magnet 127 operates to make connections over theprivate wires. In order to lock down the arm 113 of the cross-head 112to hold the pins 38 in contact with the different contact-points, weprovide the armature 128 with an arm 131, which projects therefrom andis provided with a hook 132 in its end, as shown in Figs. 1 and 2. Thehook 132 is adapted to fit into a recess 133 in a bar 134, which ispivotally mounted upon the baseplate 20 in a vertical position and isheld normally in substantially a vertical position in a block 135.

136 indicates a spring which bears against one side of the bar 134 andtends to press it outward from the magnet 127, the arrangement beingsuch that when the armature 128 The cross head (See Fig. i

-145, as shown in Fig. 6.

is attracted by the magnet 127 the hook 132 will be moved down farenough to enter the recess 133, and the spring 136 will then move thebar 134 suffieiently to cause the hook 132 to enter such recess. The bar134 is pressed back toward the magnet 127 to release the armature 128 bymeans of a rod 137, which projects from the rear end of the armature103, as best shown in Fig. 1, which bar is adapted to strike the bar 134on the side opposite the spring 136 when the armature 103 is attractedby the magnet 102 and to move said bar 134 sufficiently to withdraw thehook 132 from the recess 133. The spring 122 will then move the armature128 upward, permitting the cross-head 112 to return to its normalposition. A similar locking device may be provided for locking the arm114 down, if desired.

In order to actuate the different magnets hereinbefore described, weprovide a set of contact-points 138, which are arranged in the arc of acircle upon the segmental plate 81, as shown in Fig. 1. The connectionsfrom the contactpoints 138 to the difierent magnets will be hereinafterdescribed.

139 indicates a circuit-closing arm, which is pivoted upon a shaft 140,(see Fig. 2,) at the center of the circle of which the contact-points138 form an arc. The shaft 140 is normally held in such position thatthe circuit-closing arm 139 rests normally upon the contact-point 138 atthe right-hand end of the are by a spring 141 on the shaft 140, as bestshown in Fig. 2. The shaft 140 is rotated to move the circuitclosing arminto contact with the different contact-points by means of anelectromagnet 142, arranged upon the base-plate 20, adjacent to themagnet 92, as shown in Fig. 6. The magnet 142, which on Fig. 9 is markedOperating-magnet, is adapted to attract an armature 143, which isarranged similarly to the armature 93, being pivoted upon a pivot 144,rising from the base-plate 20. The armature 143 carries a horizontal arm145, which extends forward and carries a pawl 146 substantially at rightangles thereto, which pawl is adapted to engage the teeth of a segmentalratchet-plate 147, mounted upon the shaft 140, as shown in Fig. 6. Whenthe magnet 142 is energized, the armature 143 will be attracted and thepawl 146 will engage the teeth of the ratchet-plate 147, moving it thespace of one tooth for each electric impulse which passes through saidmagnet. The spring 98 serves to move the armature 143 away from thepoles of the magnet 142, as it is connected to the rear end of the armBy this arrangement the spring 98 serves to operate both arms 94 and145. The spring 141, which is mounted upon the shaft 140, serves toreturn the ratchet-plate 147 and the shaft 140 to their normal position.

149 indicates an adjustable stop to limit return motion of theratchet-plate 147. Return movement of the ratchet-plate 147 is prevented by a dog 150, (see Fig. 6,) which is pivoted in the block and isadapted to engage the teeth of the ratchet; plate 147, as shown in Fig.6, being heldin engagement with said teeth by a spring 151. The dog isthrown out of engagement with the teeth of the ratchet-plate 147 topermit of the return of said plate to its normal position by means of aconnecting-rod 152, (see Fig. 6,) one end of which is connected to therod 108, its other end being connected to an arm 153, which is rigidlysecured to the dog 150, substantially at right angles thereto. By thisconstruction when the release-magnet 102 is energized the dogs 99 and150 will be thrown out of engagement with the respective rack-platessimultaneously, thereby permitting both of said rack-plates to return totheir normal position.

154 155 indicate standards in which are fitted screws 156, which serveas stops to limit the outward motion of the arms 145 94 respectively, asshown in Fig. 6.

157 (see Fig. 1) indicates an electromagnet which is mounted upon thebaseplate 20 and is provided with an armature 158, which is pivoted uponthe base-plate 20 and is in electrical connection therewith. The magnet157 is marked Push-button magnet on Fig. 9. The armature 158 carries anarm 159, which is adapted to engage a plate (see Fig. 2) when saidarmature is attracted by the magnet 157, thereby forming an electricalconnection between said plate 160 and the base-plate 20. The armature158 is held normally in such position as to hold the arm 159 out ofcontact with the plate 160 by means of a suitable spring, as bestshownin Figs. 1 and 2.

161 (see Fig. 7) indicates an electromagnet marked Substationcontrolling-magnet on Fig. 9, which is mounted upon the base-plate 20and is provided with a pivoted armature 162, which is in electricalconnection with the base-plate 20. The armature 162 is pivoted upon arod 163, mounted in standards 164 165, (see Fig. 22,) rising from thebase-plate 20, as best shown in Figs. 2 and 22.

166 167 indicate two metallic plates which are insulated from each otherand from the base-plate 20, the plate 167 being adapted to be engaged byan arm 168, secured to the armature 162, when said armature is notattracted by the magnet 161, said armature being normally held away fromthe poles of said magnet 161 by means of a spring 169, arranged upon therod 163, as shown in Fig. 22. When the magnet 161 is energized, thearmature 162 will be attracted thereby, thereby disconnecting the arm168 from the plate 167.

The right-hand contact point 138, upon which the circuit-closing arm 139normally rests, which contact-point we have indicated by a, (see Fig.9,) is connected to the switchboards 22 of all the otherexchange-switches in the system by a wire 170, (see Fig. 9,) which wireis connected to the general and private contact-points upon suchswitchboards bearing the number of the exchange-switch from which saidwire originated. The contact-point b, which is next in order. isconnected by a wire 171 to one end of the coil of the magnet 92. Theother end of such coil is connected by wires 1'72 and 173 to a battery176, as shown in Fig. 9. The opposite pole of the battery 176 isconnected by wires 177 and 179 to a plate 180, which is secured upon theplate 81 andlies over or opposite the contact-point 138, which is marked6 in Fig. 9 and is the fifth in succession from the right-hand end ofthe series of contact-points. The wire 179 is also connected to plate160. In Fig. 9 the plate 180 has been illustrated as having acontactpoint arranged opposite the contact-point 0. The wire 172 is alsoconnected by wire 174 to one end of the coil of the magnet 127, as shownin Fig. 9, and by wires 181 182 183 184 to'one end of the coils of eachof the magnets 117 63 74 53, respectively, as shown in Fig. 9;

185 indicates a wire which connects contactpoint 0, Fig. 9, to theopposite end of the coil of the magnet 63.

186 indicates a wire which connects con tactpoint (Z, Fig. 9, to theopposite end of the coil of the magnet 53. V

187 indicates a wire which connects the contact-point e to the oppositeend of the coil of the magnet 117.

188 indicates a wire which connects contactpoint f, Fig. 9, to theopposite end of the coil of the magnet 127.

189 indicates a wire which connects contactpoint g to one end of thecoil of the magnet 102.

190 indicates a wire which connects the wire 189 with a plate 191. whichis insulated from the base-plate 20 and is so placed that when thearmature 103 is attracted by the magnet 102 said armature or the rod107, which is in electrical connection therewith, will strike the plate191, making electrical connection therewith. The armature 103 is inelectrical connection with the base-plate 20 by a wire 210. Thearrangement of the plate 191 and armature 103 is shown in Figs. 1 and 9.

192 indicates a wire which connects the opposite end of the coil of themagnet 102 with the other end of the coil of the magnet 74.

The armature 158 is connected to the base plate 20 or wire 20.

194 indicates a wire connecting one end of the coil of the magnet 157 toplate 167.

193 indicates a wire which connects the armature 162 with the base-plate20 or wire 20". hen not attracted by the magnet 161, the arm 168 of thearmature 162 is in contact with the plate 167. r

195 indicates a wire which connects the plate 166 to a plate 196, placedopposite the armature 103 and on the opposite side from the magnet 102,as shown in Fig. 9.

197 indicates a second plate, which is placed opposite the plate 196, asshown in Fig. 9, both of which plates 196 197 are insulated from thebase-plate 20. The arrangement is such that when the armature 103 is notattracted by its magnet 102 it will be in electrical contact with theplates 196 197.

198 indicates a wire which connects the plate 197 with one end of thecoil of the magnet 142. 199 indicates a wire which connects the otherend of the coil of the magnet 142 with a battery 202. 203 indicates awire connecting the opposite pole of the battery 202 with acontact-point 206, which in practice (see Fig. 22) is carried by the arm168, which is attached to the armature 162. The eontactpoint 206 isinsulated from the arm 168 and is adapted to strike the plate 166 whenthe armature 162 is not attracted by the magnet 161.

207 indicates a ground-wire, one end of which is connected to a battery208.

209 indicates a wire connecting the battery 208 to one end of the coilof the magnet 161.

214 indicates a wire which connects themagnet 161 to thesubstation-switchboard.

215 indicates a wire connecting the substation-switchboard to thebase-plate 20.

The way in which the wires 214 215 are connected to thesubstationswitchboard will be hereinafter explained.

217 indicates a wire connecting the other end of the coil of the magnet157 to the wire 209.

The connections of the contact-points 82 have been hereinbeforedescribed. The circuit-closing arm 83, which moves over suchcontact-points 82, is in electrical connection with the base-board 20.

e will now describe the construction of the substation-SWitchboard andafterward the method of operating it to connect the operators instrumentwith any other in the system through his exchange-switch and will thenexplain further the method in which the different circuits in theexchange-switch are established.

218 indicates a substation-switchboard, the frame of which consists ofan upper plate 219 and a lower plate 220, which are secured together bysuitable posts 221, as shown in Figs. 12 and 14. The top plate 219 ismade of some suitable non-conducting material and is provided upon itsupper surface with a series of contact-points 222 223 224 225 226 227,

which are arranged in the circumference of a circle. The contact-points222 225 226 227 are preferably circular; but the contactpoints 223 224are segmental in shape and are arranged to project radially toward thecenter of the circle, as shown in Fig. 11.

228 229 230 indicate three contact-points arranged within the circleupon the top plate 219, as shown in Fig. 11. On the under side of thetop plate 219 the contact-points 222 223 224 225 226 227 areelectrically connected by a metallic band 231, as shown in Fig. 12. andthe three contact-points 228 229 230 are connected on the under side ofsaid top plate 219 by a metallic plate 232, as also shown in Fig. 12.

233 indicates a shaft which is mounted b'e tween the two plates 219 220at the centerof the circle formed by the connecting-strap 231. The shaft233 is in electrical connection with the lower plate 220 and carriesabove the top plate 219 two arms 234 235, which are insulated from eachother, as shown in Fig. 14, the arm 234 being also insulated from theshaft 233. The arm 235 is in electrical connection with said shaft. Thearm 234 is of suflicient length to rest upon the contact-points 222 223224 225 226 227, so that by rotating the shaft 233 said arm may be movedinto contact with any of said contact-points. The arm 235 is shorter andis adapted to be moved into contact with the contact-points 228 229 230,as shown. Both of the arms 234 235 are preferably made of spring metaland are arranged to bear upon the different contact-points suflicientlyto secure a good contact. The shaft 233 is adapted to be rotated bymeans of a crank 236, which is mounted upon a shaft 237, journaled insuitable bearings 238, mounted upon the lower plate 220, as shown inFigs. 13 and 14.

Mounted upon the shaft 237 is a worm 239, which is adapted to engage apinion 240, mounted upon the shaft 233, as shown in Figs. 13 and 14. Bythis arrangement by rotating the shaft 237 by means of the crank 236 theshaft 233 may be rotated.

241 indicates a flat spring which is secured upon the lower plate 220and is adapted to rest upon a plate 242, which is mounted upon the shaft237, as indicated by dotted lines in Figs. 13 and 14. The plate 242 iscircular in shape except that one portion of its periphery is flattened,so that when the spring 241 rests upon said flattened portion of theplate 242 the crank 236 will be held stationary. The plate 242, pinion240, and worm 239 are so arranged that when the crank 236 is rotated thespring 241 will rest upon the flattened portion of the plate 242 whenthe arm 234 rests upon the contact-point 222, when said arm is at apoint between the contact-points 222 and 223, when said arm is betweencontact-points 223 and 224, when said arm is between contact-points 224and 225, when said arm rests upon contact-points 226 and 227. hen thearm 234 rests upon contact-point 226, the arm 235 will rest uponcontact-point 228, which is diametrically opposite contactpoint 226, asshown in Fig. 11. Also when the arm 234 rests upon contact-point 227 thearm 235 will rest upon contact-point 229, and when the arm 234 restsupon contactpoint 222 the arm 235 will rest upon contactpoint 230, asindicated by dotted lines in Fig. 11.

243 indicates a push-button which is fitted in a suitable perforation inthe upper plate 219 and is connected at the under side of said plate toa spring-plate 244, which is secured to said plate 219.

245 indicates a metal pin which is secured to the lower plate 220 andprojects upward, terminating near the spring-plate 244. The arrangementis such thatby pressing the pushbutton 243 the plate 244 will be movedinto contact with the pin 245. (See Fig. 18.)

246 indicates a bar which is secured to the plate 219 and extends overthe top of the shaft 233, which is supported by said bar 246, but isinsulated from it.

247 indicates a spring which isconnected to the bar 246 and bears uponthecentral portion of the arm 234, so that as said arm 234 rotates itwill always be in electrical connection with the bar 246.

The wire 214 is connected to the bar 246 at the under side of the plate219, as shown in Fig. 14 and as indicated in Fig. 15. The wire 215,which is connected to the base-plate 20 of the exchange, is connected tothe lower plate 220 of the substation-switch, as shown in Figs. 14 and15.

248 indicates a wire which connects the ring 231 with a binding-post249, to which is also connected the push-button plate 244, as shown inFigs. 12 and 15.

250 indicates the subscribers telephone.

251 indicates a wire leading from the telephone to the plate 232, asshown in Fig. 15.

252 indicates a second telephone-wire, which is grounded, 'as shown inFig. 15'.

253 indicates a wire which connects the binding-post 249 to the wire252, as shown in Fig; 15 1 \Ve will now describe the manner ofconnecting the subscribers telephone through his exchange-switch withany other telephone in the system. i

The normal position of the subscribers switchboard 218 is shown in Fig.15, the arm 234 resting upon contact-point 222 and the arm 235 restingon contact-point 230. The circuit is normally open and is as follows:from the ground, over wire 252, through the operators telephone, thenceover wire 251 to plate-232, thence through arm 235 to lower plate 220 ofthe substation-switchboard, thence over wire 215 to base-plate 20 orwire 20, thence through arm 139 to contact-point a of theexchange-switch, upon which said arm normally rests, thence over wire170 to the other exchange-switches in the system. At.

the same time a closed circuit will be established from the ground, overwires 252, 253, and-248, to ring 231, thence to contact-point 222,thence through arm 234 to wire 214,

thence through electromagnet 161, back on wire 209, through battery 208to the ground over wire 207. The magnet 161 will therefore be energized,and its armature 162 will be attracted by it, thereby holding its arm168 out of contact with plate 167 and holding the contact-point 206 outof engagement with the plate 166. lVhen the apparatus is in thisposition, the subscriber may call up any other subscriber in the system,as connection may be made with his instrument by operating any of theother exchange-switches in the system.

If new the subscriber should desire to establish communication withtelephone No. 356, by means of the crank 236 he would give the shaft 237one complete revolution in such a direction as to cause the shaft 233 torotate in the direction opposite to that in which the hands of a clockmove. As soon as the arm 234 moves out of contact with the contactpoint222 the circuit through the magnet 161 will be broken, demagnetizingsaid magnet, whereupon its armature 162 will be released, and, as hasbeen hereinbefore described, the circuit will be closed bet-ween thecontact-point 206 and plate 166 and also between the baseplate 20 an'dplate 167 through armature 162 and its arm 168. The result of thisaction I will be that a circuit will be established through magnet 142,the course of the current being from magnet 142, through wire 198, toplate 197, thence through armature 103 to plate 196, thence through wire195 to plate 166, thence through pin 206 to wire 203, thence throughlocal battery 202 and wire 199 back to the magnet 142. The magnet 142will thereby be energized and, as above described, will operate to shiftthe 'arm'139 into contact with the adjacent contact-point b. Theconnections will now be as follows: from base 20 or wire 20 of theexchange, through arm 139, to the contact-point b, thence over wire 171to electromagnet 92, thence over wires 172 and 173 to battery 176,thence over wires 17 7 and 179 to plate 160. The circuit will not beclosed,- owing to the fact that the electromagnet 157 is not energized,and consequently the armature 158 will not be in contact with the plate160. At this time the following connections will also exist: from thelower plate 220 of the substation -switchboard, over wire 215, tobase-plate 20 or wire 20 of the exchange switch, thence through armature162 and arm 168 (the arm 168 is not shown in Fig@ I net 157. willthereby be attracted, bringing the contact-arm 159 of the armature 158(see Fig. 2) into contact with the plate 160, thereby connecting thewire 17 9 to the base-plate 20 and closing the circuit throughelectromagnet 92. The arm 83 will thereby be caused to move into contactwith the next contact-point 82, and the operator will then be in aposition to effect an electrical connection with contactpoints of anexchange-switchboard numbered from 100 to 199. In order to makeconnection with telephone No. 356, he would therefore press thepush-button 243 three times, when the arm 83 of his exchange-switchwould be moved into contact with the fourth contact-point 82 from theleft, and the operator would then be in position to operate thecircuit-closing devices of his exchange-switchboard the proper number oftens and units. The subscriber would now give the crank 236 anadditional rotation, bringing the arm 234 to a point betweencontact-points 223 and 224. In moving to such point the arm 234 willmove over contact-point 223 and will thereby momentarily close thecircuit through electromagnet 161, the circuits being the same as thoseestablished when the arm 234 is in its normal position. The closing ofthe circuit through magnet 161 would cause it to attract its armature162, thereby breaking the circuit through electromagnet 142 andreleasing its armature 143. The pawl 146 would then move back and wouldbe in position to engage the next succeeding tooth of the segmentalrack-plate 147, when the mag net 142 will again be energized. This wouldbe effected as soon as the arm 234 moves off the contact-point 223, andtherefore the magnet 142 would again be automatically energized and thearm 139 would be moved, as before, the space of one tooth of theratchetplate 147, bringing it into contact with the contact-point 0. Theconnections would then be as follows: from the base-plate 20 of theexchange-switch, through arm 139, to contactpoint 0, thence through wire185 to electromagnet 63, thence over wires 182 172 173, battery 176,wires 177 179 to plate 160, when, as before, the circuit can becompleted to the base-plate 20 by operating the push-button 243,andthereby energizing the magnet 157. As will be remembered, theelectromagnet 63 operates the mechanism for moving the shaft 25longitudinally of the switchboard 22 and each electrical impulse whichpasses through said magnet moves the circuit-closing pins in position tocome into contact with the next row of ten contact-points. In order tomove the contact-points in position to engage a contact-point in thefifties, the operator would operate his push-button five times, sendingfive impulses through the electromagnet 63 and moving thecircuit-closing pins into posi tion over the sixth row ofcontact-points.

The armature 158 of said magnet The subscriber would now give his crank236 another complete revolution, thereby moving the arm 234 to a pointbetween contact-points 224 and 225, said arm moving across the surfaceof contact-point 224, as when said arm moved across contact-point 223the circuit would again be closed through magnet 161 and the magnet 142would again be cut out, as above described. As soon as the arm 234 movesoff of contact-point 224 the magnet 161 would be cut out and magnet 142accordingly cut in, as above described, thereby moving the arm 139 intocontact with contact-point cl. Connections would thereby be made asfollows: from the baseplate 20 and arm 139 to contact-point (Z, thenceover wire 186 to electromagnet 53, thence over wires 184 172 17 3,battery 176, thence over wires 177 179 to plate 160. By then pressingthe push-button 243 the circuit would be closed through magnet 157,closing the circuit to base 20 or wire 20 through armature 158 andenergizing magnet 53, thereby moving the shaft 25 the space of one toothof the ratchet-wheel 58. As hereinbefore described, the magnet 53operates to move the circuit-closing pins units, and therefore bypressing the push-button 243 six times the circuit-closing arm wouldmove opposite the sixth contact-point on the exchange-switch board. Oneof the circuit-closing pins 38 would now lie opposite the upper andlower contact-points of the exchange-switchboard numbered 356, the lowercontact-point being connected by a general wire to the otherexchange-switehboards and the. upper contactpoint being connected by aprivate wire to the other switchboards in the system. The methodofconnecting the private and general wires will be more fullyhereinafter set forth. If the subscriber does not wish to usethe privatewire, he now rotates the crank 236 again, thereby moving the arm 234into contact with contact-point 226 and arm 235 into contact withcontact-point 228. Before reaching contact-point 226, however, arm 234passes over contact-point 225, thereby again closing the circuitmomentarily through electromagnet 161 and cutting out magnet 142. Themagnet 161 is immediately cut out when the arm 234 moves offcontact-point 225, thereby again energizing magnet 142 and moving thearm 139 into contact with eontaet-pointeand plate 180. A closed circuitwill thereby be established from contact-point a over wire 187 to magnet117, thence over wires 181 174 172 173 to battery 176, thence over wires177 179 to plate 180, and thence through arm 139 to contact-point Thecircuit will thereby be closed through magnet 117, which will beenergized, and the cross-head 112 will be caused to tilt, moving therear portions of the bars 32 33 34 35 36 downward into contact with thecontact-points upon the lower plate 24 and the forward portions of saidbars upward into contact with the upper plate 23.

